The only detox like reactions I've ever had were when I was taking 6000 - 8000mg daily. I took this amount in the first place to try to fade dark brown facial pigmentation that I developed as a result of taking Minocyclene (Minocin) antibiotic on and off for two and a half years - to treat said acne, prescribed by a doctor (allopathic, who by the way didn't tell me to take probiotics to replace the good bacteria it killed). The symptoms I experienced were a headache, not severe, I was a little tired - I started to crave water and fruit and I became nauseous upon drinking beer(!). Typical detox reaction, and not very severe.
So, 1000, 2000 even 3000mg wouldnt really have much of an effect - but everyone's different. Start with 1000mg, work up to whatever dosage you reckon you need.
It's a great supplement, I'm really glad I found it - I can totally identify with the whole body dysmorphic thing - I was obsessed with my skin when it was bad. It's really nice now, totally clear.
BTW I got rid of any scarring with rosehip oil, it works really well... they use it on burns victims apparently because of its healing powers